Protagonist Therapeutics notches a milestone in its pact with Takeda for rusfertide. New data show that many patients with a chronic blood cancer taking the drug didn’t need to have their blood removed to bring down dangerously high hemocrit levels.
Takeda and Protagonist Therapeutics’ medicine for a chronic type of blood cancer saw 77% of patients respond, without needing blood withdrawals, when compared to placebo in a Phase II clinical trial. Protagonist, which will receive a $25 million milestone from Takeda thanks to the positive results, plans to submit the findings to regulators. Shares of Protagonist climbed 6% as the market opened Monday morning to $39.92, compared to a prior close of $37.59.
Rusfertide is being developed to treat polycythemia vera, a type of rare and incurable cancer that causes the bone marrow to produce too many red blood cells. This can lead to a thickening of the blood and blood clots, as well as cardiovascular and thrombotic events. Patients are typically treated with regular phlebotomy procedures, where blood is removed from the body to manage the elevated hematocrit levels caused by having too many red blood cells. The procedure itself can cause fatigue, visual disturbances and iron deficiency. The goal of phlebotomy is to reduce hematocrit levels to below 45%.
In the Phase III VERIFY trial, rusfertide achieved the main goal, which was the proportion of patients who didn’t need phlebotomy in weeks 20 through 32. Patients treated with the study drug and standard of care had a response rate of 77%, compared to 33% on placebo and standard of care.
Rusfertide also met all four key secondary endpoints. The first was an endpoint used by European regulators, which looks for the reduction in the number of phlebotomy procedures. The drug achieved a mean of 0.5, compared to 1.8 in the placebo group. Measures of hematocrit control, patient reported outcomes of fatigue and other symptoms also improved on rusfertide.
On safety, the drug was generally well tolerated and in line with previous studies, according to Protagonist. The majority of reported adverse events were low grade injection site reactions and all serious adverse events were deemed to be unrelated to the study drug. There was also no evidence of an increase in cancer risk in patients who received rusfertide.
Additional details from the study will also be presented at a future medical meeting.
Takeda and Protagonist signed the licensing deal for rusfertide in January 2024. The biotech received $300 million upfront with additional undefined milestones available down the line. Protagonist is in charge of development through the end of Phase III and U.S. regulatory approval. Then Takeda will take over global commercialization activities.
This is the second time in five months that Protagonist has reported late-stage success in the clinic. In November 2024, the company’s Johnson & Johnson-partnered drug icotrokinra improved symptoms of plaque psoriasis in the pivotal ICONIC-LEAD and ICONIC-TOTAL trials. From that program, Protagonist has already earned $165 million, with $630 million more possible based on future milestones.
